A New Tool for Solving Crimes: Pollen

Pollen—it can make you sneeze or cough, it’s a reason to get out the dust cloth and polish. Most people think of pollen as a nuisance… but can it help solve crimes?

Vaughn Bryant, a Texas A&M professor of anthropology, is among a very few experts in the United States who knows that it can. For over 30 years, Dr. Bryant has taken a keen interest in forensic palynology – the use of pollen to investigate criminal cases.

Why is pollen so useful to criminal investigators? The answer lies in its geographic specificity. There are about 500,000 different plant species worldwide, and each of them produces its own unique kind of spore or pollen, which is spread by the wind or animal activity. The distinctive combination of plants in any given area thus yield very specific “pollen prints”, like fingerprints in humans. Scientists like Texas A&M’s Dr. Bryant, who are trained in both botany and palynology, know the life cycle and dispersion patterns of the various plants. In criminal investigations in which pollen samples have been collected, experts can use them to link an weapon or a suspect to a crime scene,  determine the specific location of a crime, what time of year it took place, and whether evidence has been removed from its original location.

So pollen and spores make up a distinctive signature of life, and constitute invisible clues at crime scenes… clues that could help convict murderers, terrorists and other violent criminals by tying them to those scenes.

Vaughn Bryant became interested in forensic palynology when he was first asked, by the U.S. Department of Agriculture in the mid-1970s, to analyze honey samples. USDA officials suspected that some beekeepers were selling inexpensive, imported honey to a government subsidy program intended for buying exclusively domestic honey. Ever since that first request, Dr. Bryant has continued analyzing honey for the USDA as well as private importers and exporters to verify premium honey types, which command high prices. In fact, since 1975, Bryant has examined more than 1,500 honey samples, and has become very familiar with specific regional “pollen prints” present in most parts of North America. But honey studies are just one of the many areas where Dr. Bryant is using pollen to catch criminals.

Dr. Bryant is well aware of the need for, and benefits of, pollen evidence, which is frequently used elsewhere in the world to fight terrorism and convict individuals responsible for acts of genocide. But though the American scientific community has the experience, pollen samples, reference collections, and analytical technology to make forensic palynology a valuable tool for investigators, U.S. law enforcement agencies have yet to take advantage of this relatively unfamiliar, but powerful, forensic technique. Dr. Bryant thinks it will probably take a high-profile criminal case before US authorities will recognize  the value of forensic palynology. As he told a reporter for the Division of Research and Graduate Studies’ Advance magazine recently: “Get me a piece of Osama bin Laden’s clothing, and the pollen will tell me where he is hiding.”

Now there’s a crime-fighting tool that’s nothing to sneeze at!